Spurious Turn-On inside a Power Module of Paralleled SiC MOSFETs

Abstract Silicon carbide (SiC) dice are often paralleled to realize power modules with high-current rating. Owing to the large network of interconnect (parasitic) impedances, terminal waveforms could appear benign while the dice experience detrimental fault currents generated by spurious cross-turn-on. This paper will quantify the non-uniform distribution of current stress and switching energy among the dice, as well as the penalty caused by cross-turn-on, versus layout symmetry, number of dice, gate resistance, input voltage, and load current. Cross-turn-on currents inside a module increase the high-side switching energy and total switching energy by 44% and 20%, respectively, at 800 V / 300 A. Peak cross-turn-on current of the symmetrical module is only 16% of that of asymmetrical module at nominal condition. Symmetrical layout greatly decreases the cross-turn-on currents without increasing the total switching energy. Four modules are constructed based on the asymmetrical layout to explore how number of...